The United States Postal Service (USPS) delivers millions of pieces of mail on a daily basis to over a million domestic addresses. Each day, before a carrier begins to walk through or drive through his or her delivery route, it is the carrier's responsibility to put all of this mail into an appropriate sequence for efficient delivery. Under the present USPS procedure, the carrier assembles at least three delivery order sequenced stacks of mail, including letters, flats (including enveloped and non-enveloped magazines), and parcels. At each delivery stop the carrier selects the items for that address from each of the various stacks and puts them all into the postal patron's mailbox. This sorting and shuffling through various stacks of mail is time consuming, inefficient, and consequently expensive to the USPS. Consequently, any reduction in amount of hand sorting done by the carriers represents the potential for increased efficiency.
To place mail in order by destination, a Delivery Bar Code Scanner (DBCS) and/or Carrier Sequence Bar Code Scanner (CSBCS) DBCS machine is typically utilized in a multi-pass sorting scheme. Two- and three pass schemes based on significant digits of the delivery points are most common. Multi-pass sorting strategies are set forth in U.S. Pat. No. 5,363,971, the disclosure of which is incorporated herein by reference. In general, a multi-pass sort scheme starts with a disordered collection of mail and sorts the mail into intermediate batches of partially sorted mail according to a first sorting criteria. The intermediate batches are fed back into the sorter again for sorting according to a second pass sort scheme. The process may be repeated several times until the mail is sorted into delivery order, depending upon the number of available bins and the number of destination points.
The result of this sorting process is, as noted above, multiple stacks of delivery ordered mail. In order to identify, for example, letters addressed to a specific address, the carrier “thumbs” through the stack, finding the first and last item addressed to the particular delivery point and separates the letters addressed to that address from the stack. This time consuming process is repeated with the stack of flats.
The invention set forth below provides a method of reducing the amount of hand sorting and stack handling required by providing the mail to the carrier in bundles corresponding to stops on the carrier's route.